ERPC Getting Started User’s Guide E RPC User's

User Manual:

Open the PDF directly: View PDF PDF.
Page Count: 26

DownloadERPC Getting Started User’s Guide E RPC User's
Open PDF In BrowserView PDF
NXP Semiconductors
User's Guide

Document Number: MCSDKERPCGSUG
Rev. 6, 05/2018

eRPC Getting Started User’s Guide

Contents

1 Before you begin

1

Before you begin............................... ........................1

This Getting Started User's Guide shows software developers
how to use Remote Procedure Calls (RPC) in embedded
multicore microcontrollers (eRPC).

2

Create an eRPC application.................... .................. 1

3

eRPC example............................ ...............................2

Additionally, see eRPC documentation located in the
following folder: /
middleware/multicore/erpc/doc folder.

3.1

Designing the eRPC application. ...................2

3.2

Creating the IDL file.................. ....................3

3.3

Using the eRPC generator tool..... ..................3

3.4

Creating eRPC applications............................4

2 Create an eRPC application

This section describes a generic way to create a client/server
eRPC application:
1. Design the eRPC application: Decide which data types
are sent between applications, and define functions that
send/receive this data.
2. Create the IDL file: The IDL file contains information
about data types and functions used in an eRPC
application, and is written in the IDL language.
3. Use the eRPC generator tool: This tool takes an IDL
file and generates the shim code for the client and the
server-side applications.
4. Create the eRPC application:
a. Create two projects, where one project is for the
client side (primary core) and the other project is
for the server side (secondary core).

3.5

3.4.1

Multicore server
application....................... ................ 5

3.4.2

Multicore client
application....................... .............. 13

3.4.3

Multiprocessor server
application......................... ............ 21

3.4.4

Multiprocessor client
application......................... ............ 22

Running the eRPC application.... .................24

4

Other uses for an eRPC implementation.. .............. 25

5

Revision history.......................... ............................ 25

eRPC example

b. Add generated files for the client application to the client project, and add generated files for the server
application to the server project.
c. Add infrastructure files.
d. Add user code for client and server applications.
e. Set the client and server project options.
5. Run the eRPC application: Run both the server and the client applications. Make sure that the server has been run
before the client request was sent.
A specific example follows in the next section.

3 eRPC example
This section shows how to create an example eRPC application called “Matrix multiply”, which implements one eRPC
function (matrix multiply) with two function parameters (two matrices). The client-side application calls this eRPC function,
and the server side performs the multiplication of received matrices. The server side then returns the result.
For example, use the NXP LPCXpresso54114 board as the target dual-core platform, and the IAR Embedded Workbench®
for ARM (EWARM) as the target IDE for developing the eRPC example.
• The primary core (CM4) runs the eRPC client.
• The secondary core (CM0+) runs the eRPC server.
• RPMsg-Lite (Remote Processor Messaging Lite) is used as the eRPC transport layer.
The “Matrix multiply” application can be also run in the multi-processor setup. In other words, the eRPC client running on
one SoC comunicates with the eRPC server that runs on anothe SoC, utilizing different transport channels. It is possible to
run the board-to-PC example (PC as the eRPC server and a board as the eRPC client, and vice versa) and also the board-toboard example. These multiprocessor examples are prepared for selected boards only.

Table 1. File locations
Multicore application source
and project files

/boards/lpcxpresso54114/multicore_examples/
erpc_matrix_multiply_rpmsg/

Multiprocessor application
source and project files

/boards//multiprocessor_examples/
erpc_client_matrix_multiply_/
/boards//multiprocessor_examples/
erpc_server_matrix_multiply_/

eRPC source files

/middleware/multicore/erpc/

RPMsg-Lite source files

/middleware/multicore/rpmsg_lite/

3.1 Designing the eRPC application
The matrix multiply application is based on calling single eRPC function that takes 2 two-dimensional arrays as input and
returns matrix multiplication results as another 2 two-dimensional array. The IDL file syntax supports arrays with the
dimension length set by the number only (in the current eRPC implementation). Because of this, a variable is declared in the
IDL dedicated to store information about matrix dimension length, and to allow easy maintenance of the user and server
code.
For a simple use of the two-dimensional array, the alias name (new type definition) for this data type has is declared in the
IDL. Declaring this alias name ensures that the same data type can be used across the client and server applications.

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
2

NXP Semiconductors

eRPC example

3.2 Creating the IDL file
The created IDL file is located in the following folder:
/boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/service/
erpc_matrix_multiply.erpc
The created IDL file contains the following code:
program erpc_matrix_multiply
/*! This const defines the matrix size. The value has to be the same as the
Matrix array dimension. Do not forget to re-generate the erpc code once the
matrix size is changed in the erpc file */
const int32 matrix_size = 5;
/*! This is the matrix array type. The dimension has to be the same as the
matrix size const. Do not forget to re-generate the erpc code once the
matrix size is changed in the erpc file */
type Matrix = int32[matrix_size][matrix_size];
interface MatrixMultiplyService {
erpcMatrixMultiply(in Matrix matrix1, in Matrix matrix2, out Matrix result_matrix) ->
void
}

Details:
• The IDL file starts with the program name (erpc_matrix_multiply), and this program name is used in the naming of all
generated outputs.
• The declaration and definition of the constant variable named matrix_size follows next. The matrix_size variable is
used for passing information about the length of matrix dimensions to the client/server user code.
• The alias name for the two-dimensional array type (Matrix) is declared.
• The interface group MatrixMultiplyService is located at the end of the IDL file. This interface group contains only one
function declaration erpcMatrixMultiply.
• As shown above, the function’s declaration contains three parameters of Matrix type: matrix1 and matrix2 are input
parameters, while result_matrix is the output parameter. Additionally, the returned data type is declared as void.
When writing the IDL file, the following order of items is recommended:
1. program name at the top of the IDL file.
2. followed by new data types and constants declarations.
3. followed by declarations of interfaces and functions at the end of the IDL file.

3.3 Using the eRPC generator tool
Table 2. eRPC generator application file locations
Windows® OS

/middleware/multicore/tools/erpcgen/Windows

Linux®

/middleware/multicore/tools/erpcgen/Linux_x64
/middleware/multicore/tools/erpcgen/Linux_x86

OS

Mac® OS

/middleware/multicore/tools/erpcgen/Mac

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

3

eRPC example

The files for the “Matrix multiply” example are pre-generated and already a part of the application projects. The following
section describes how they have been created.
• The easiest way to create the shim code is to copy the erpcgen application to the same folder where the IDL file
(*.erpc) is located; then run the following command:
erpcgen .erpc

• In the “Matrix multiply” example, the command should look like:
erpcgen erpc_matrix_multiply.erpc

Additionally, another method to create the shim code is to execute the eRPC application using input commands:
• “-?”/”—help” – Shows supported commands.
• “-o ”/”—output” – Sets the output directory.
For example,
/erpcgen –o 
/.erpc

For the “Matrix multiply” example, when the command is executed from the default erpcgen location, it looks like:
erpcgen –o

../../../../../boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/service ../../../../../boards/
lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/service/erpc_matrix_multiply.erpc
In both cases, the following four files are generated into the /boards/lpcxpresso54114/
multicore_examples/erpc_matrix_multiply_rpmsg/service folder.
• erpc_matrix_multiply.h
• erpc_matrix_multiply_client.cpp
• erpc_matrix_multiply_server.h
• erpc_matrix_multiply_server.cpp
For multiprocessor examples, the eRPC file and pre-generated files can be found in the /
boards//multiprocessor_examples/erpc_common/erpc_matrix_multiply/service folder.
For Linux OS users:
• Do not forget to set the permissions for the eRPC generator application.
• Run the application as ./erpcgen … instead of as erpcgen ….

3.4 Creating eRPC applications
This section does not show how to create a dual-core application from scratch. Instead, it discusses individual source file
groups that form the eRPC applications. You can use the dual-core examples provided within the Multicore SDK (MCSDK)
package as a starting point (and reference) for cloning these source files to individual user projects.
For more information about building, running, and debugging multicore example applications in different supported
toolchains, see the Getting Started with MCUXpresso SDK and/or Getting Started with MCUXpresso SDK for XXX
Derivatives documents located in the /docs/ folder.
Multiprocessor setup of the eRPC application is discussed in this documentation as well. The behavior of this application is
the same as in the multicore case, with the exception that the eRPC transport layer needs to be set up correctly in the
application.
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
4

NXP Semiconductors

eRPC example

3.4.1 Multicore server application
The “Matrix multiply” eRPC server project is located in the following folder:
/boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/cm0plus/iar/
The project files for the eRPC server have the _cm0plus suffix.

3.4.1.1

Server project basic source files

The startup files, board-related settings, peripheral drivers, and utilities belong to the basic project source files and form the
skeleton of all MCUXpresso SDK applications. These source files are located in:
• /devices//boards//multicore_examples//

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

5

eRPC example

Figure 1. Server project basic source files

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
6

NXP Semiconductors

eRPC example

3.4.1.2

Server-related generated files

The server-related generated files are:
• erpc_matric_multiply.h
• erpc_matrix_multiply_server.h
• erpc_matrix_multiply_server.cpp
The server-related generated files contain the shim code for functions and data types declared in the IDL file. These files also
contain functions for the identification of client requested functions, data deserialization, calling requested function’s
implementations, and data serialization and return, if requested by the client. These shim code files can be found in the
following folder:
/boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/service/

Figure 2. Server-related generated files

3.4.1.3

Server infrastructure files

The eRPC infrastructure files are located in the following folder:
/middleware/multicore/erpc/erpc_c
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

7

eRPC example

The erpc_c folder contains files for creating eRPC client and server applications in C/C++. These files are distributed into
subfolders.
• The infra subfolder contains C++ infrastructure code used to build server and client applications.
• Four files, erpc_server.h, erpc_server.cpp, erpc_simple_server.h and erpc_simple_server.cpp,
are used for running the eRPC server on the server-side applications. The simple server is currently the only
implementation of the server, and its role is to catch client requests, identify and call requested functions, and
send data back when requested.
• Three files (erpc_codec.h, erpc_basic_codec.h, and erpc_basic_codec.cpp) are used for codecs.
Currently, the basic codec is the initial and only implementation of the codecs.
• The erpc_common.h file is used for common eRPC definitions, typedefs, and enums.
• The erpc_manually_constructed.h file is used for allocating static storage for the used objects.
• Message buffer files are used for storing serialized data: erpc_message_buffer.h and
erpc_message_buffer.cpp.
• The erpc_transport.h file defines the abstract interface for transport layer.
• The port subfolder contains the eRPC porting layer to adapt to different environments.
• erpc_port.h file contains definition of erpc_malloc() and erpc_free() functions.
• erpc_port_stdlib.cpp file ensures adaptation to stdlib.
• erpc_config_internal.h internal erpc configuration file.
• The setup subfolder contains a set of plain C APIs that wrap the C++ infrastructure, providing client and server init and
deinit routines that greatly simplify eRPC usage in C-based projects. No knowledge of C++ is required to use these
APIs.
• The erpc_server_setup.h and erpc_server_setup.cpp files needs to be added into the “Matrix multiply”
example project to demonstrate the use of C-wrapped functions in this example.
• The erpc_transport_setup.h and erpc_setup_rpmsg_lite_remote.cpp files needs to be added into the
project in order to allow the C-wrapped function for transport layer setup.
• The erpc_mbf_setup.h and erpc_setup_mbf_rpmsg.cpp files needs to be added into the project in order to
allow message buffer factory usage.
• The transports subfolder contains transport classes for the different methods of communication supported by eRPC.
Some transports are applicable only to host PCs, while others are applicable only to embedded or multicore systems.
Most transports have corresponding client and server setup functions in the setup folder.
• RPMsg-Lite is used as the transport layer for the communication between cores,
erpc_rpmsg_lite_base_transport.h, erpc_rpmsg_lite_transport.h and
erpc_rpmsg_lite_transport.cpp files needs to be added into the server project.

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
8

NXP Semiconductors

eRPC example

Figure 3. Server infrastructure files
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

9

eRPC example

3.4.1.4

Server multicore infrastructure files

Because of the RPMsg-Lite (transport layer), it is also necessary to include RPMsg-Lite related files, which are in the
following folder:
/middleware/multicore/rpmsg_lite/
The multicore example applications also use the Multicore Manager software library to control the secondary core startup
and shutdown. These source files are located in the following folder:
/middleware/multicore/mcmgr/

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
10

NXP Semiconductors

eRPC example

Figure 4. Server multicore infrastructure files

3.4.1.5

Server user code

The server’s user code is stored in the main_core1.c file, located in the following folder:
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

11

eRPC example

/boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/cm0plus
The main_core1.c file contains two functions:
• The main() function contains the code for the target board and eRPC server initialization. After the initialization, the
matrix multiply service is added and the eRPC server waits for client’s requests in the while loop.
• The erpcMatrixMultiply() function is the user implementation of the eRPC function defined in the IDL file.
• There is the possibility to write the application-specific eRPC error handler. The eRPC error handler of the matrix
multiply application is implemented in the erpc_error_handler.h and erpc_error_handler.cpp files.
The eRPC-relevant code is captured in the following code snippet:
/* erpcMatrixMultiply function user implementation */
void erpcMatrixMultiply(const Matrix *matrix1, const Matrix *matrix2, Matrix *result_matrix)
{
...
}
int main()
{
...
/* RPMsg-Lite transport layer initialization */
erpc_transport_t transport;
transport = erpc_transport_rpmsg_lite_remote_init(src, dst, (void *)startupData,
ERPC_TRANSPORT_RPMSG_LITE_LINK_ID, SignalReady, NULL);
...
/* MessageBufferFactory initialization */
erpc_mbf_t message_buffer_factory;
message_buffer_factory = erpc_mbf_rpmsg_init(transport);
...
/* eRPC server side initialization */
erpc_server_init(transport, message_buffer_factory);
...
/* Adding the service to the server */
erpc_add_service_to_server(create_MatrixMultiplyService_service());
...
while (1)
{
/* Process eRPC requests */
erpc_status_t status = erpc_server_poll();
/* handle error status */
if (status != kErpcStatus_Success)
{
/* print error description */
erpc_error_handler(status, 0);
...
}
...
}
}

Except for the application main file, there are configuration files for the RPMsg-Lite (rpmsg_config.h) and eRPC
(erpc_config.h), located in the /boards/lpcxpresso54114/multicore_examples/
erpc_matrix_multiply_rpmsg folder.

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
12

NXP Semiconductors

eRPC example

Figure 5. Server user code

3.4.2 Multicore client application
The “Matrix multiply” eRPC client project is located in the following folder:
/boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/cm4/iar/
Project files for the eRPC client have the _cm4 suffix.

3.4.2.1

Client project basic source files

The startup files, board-related settings, peripheral drivers, and utilities belong to the basic project source files and form the
skeleton of all MCUXpresso SDK applications. These source files are located in the following folders:
• /devices//boards//multicore_examples//

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

13

eRPC example

Figure 6. Client application
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
14

NXP Semiconductors

eRPC example

3.4.2.2

Client-related generated files

The client-related generated files are:
• erpc_matric_multiply.h
• erpc_matrix_multiply_client.cpp
These files contain the shim code for the functions and data types declared in the IDL file. These functions also call methods
for codec initialization, data serialization, performing eRPC requests, and de-serializing outputs into expected data structures
(if return values are expected). These shim code files can be found in the /boards/
lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg/service/ folder.

Figure 7. Client-related generated files

3.4.2.3

Client infrastructure files

The eRPC infrastructure files are located in the following folder:
/middleware/multicore/erpc/erpc_c
The erpc_c folder contains files for creating eRPC client and server applications in C/C++. These files are distributed into
subfolders.
• The infra subfolder contains C++ infrastructure code used to build server and client applications.
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

15

eRPC example

• Two files, erpc_client_manager.h and erpc_client_manager.cpp, are used for managing the client-side
application. The main purpose of the client files is to create, perform, and release eRPC requests.
• Three files (erpc_codec.h, erpc_basic_codec.h, and erpc_basic_codec.cpp) are used for codecs.
Currently, the basic codec is the initial and only implementation of the codecs.
• erpc_common.h file is used for common eRPC definitions, typedefs, and enums.
• erpc_manually_constructed.h file is used for allocating static storage for the used objects.
• Message buffer files are used for storing serialized data: erpc_message_buffer.h and
erpc_message_buffer.cpp.
• erpc_transport.h file defines the abstract interface for transport layer.
• The port subfolder contains the eRPC porting layer to adapt to different environments.
• erpc_port.h file contains definition of erpc_malloc() and erpc_free() functions.
• erpc_port_stdlib.cpp file ensures adaptation to stdlib.
• erpc_config_internal.h internal eRPC configuration file.
• The setup subfolder contains a set of plain C APIs that wrap the C++ infrastructure, providing client and server init and
deinit routines that greatly simplify eRPC usage in C-based projects. No knowledge of C++ is required to use these
APIs.
• erpc_client_setup.h and erpc_client_setup.cpp files needs to be aded into the “Matrix multiply”
example project to demonstrate the use of C-wrapped functions in this example.
• erpc_transport_setup.h and erpc_setup_rpmsg_lite_master.cpp files needs to be added into the
project in order to allow C-wrapped function for transport layer setup.
• erpc_mbf_setup.h and erpc_setup_mbf_rpmsg.cpp files needs to be added into the project in order to
allow message buffer factory usage.
• The transports subfolder contains transport classes for the different methods of communication supported by eRPC.
Some transports are applicable only to host PCs, while others are applicable only to embedded or multicore systems.
Most transports have corresponding client and server setup functions, in the setup folder.
• RPMsg-Lite is used as the transport layer for the communication between cores,
erpc_rpmsg_lite_base_transport.h, erpc_rpmsg_lite_transport.h, and
erpc_rpmsg_lite_transport.cpp files needs to be added into the client project.

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
16

NXP Semiconductors

eRPC example

Figure 8. Client infrastructure files
eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

17

eRPC example

3.4.2.4

Client multicore infrastructure files

Because of the RPMsg-Lite (transport layer), it is also necessary to include RPMsg-Lite related files, which are in the
following folder:
/middleware/multicore/rpmsg_lite/
The multicore example applications also use the Multicore Manager software library to control the secondary core startup
and shutdown. These source files are located in the following folder:
/middleware/multicore/mcmgr/

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
18

NXP Semiconductors

eRPC example

Figure 9. Client multicore infrastructure files

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

19

eRPC example

3.4.2.5

Client user code

The client’s user code is stored in the main_core0.c file, located in the following folder:
/boards/lpcxpresso54114/multicore_example/erpc_matrix_multiply_rpmsg/cm4
The main_core0.c file contains the code for target board and eRPC initialization.
• After initialization, the secondary core is released from reset.
• When the secondary core is ready, the primary core initializes two matrix variables.
• The erpcMatrixMultiply eRPC function is called to issue the eRPC request and get the result.
It is possible to write the application-specific eRPC error handler. The eRPC error handler of the matrix multiply application
is implemented in erpc_error_handler.h and erpc_error_handler.cpp files.
The matrix multiplication can be issued repeatedly, when pressing a software board button.
The eRPC-relevant code is captured in the following code snippet:
...
extern bool g_erpc_error_occurred;
...
/* Declare matrix arrays */
Matrix matrix1 = {0}, matrix2 = {0}, result_matrix = {0};
...
/* RPMsg-Lite transport layer initialization */
erpc_transport_t transport;
transport = erpc_transport_rpmsg_lite_master_init(src, dst,
ERPC_TRANSPORT_RPMSG_LITE_LINK_ID);
...
/* MessageBufferFactory initialization */
erpc_mbf_t message_buffer_factory;
message_buffer_factory = erpc_mbf_rpmsg_init(transport);
...
/* eRPC client side initialization */
erpc_client_init(transport, message_buffer_factory);
...
/* Set default error handler */
erpc_client_set_error_handler(erpc_error_handler);
...
while (1)
{
/* Invoke the erpcMatrixMultiply function */
erpcMatrixMultiply(matrix1, matrix2, result_matrix);
...
/* Check if some error occured in eRPC */
if (g_erpc_error_occurred)
{
/* Exit program loop */
break;
}
...
}

Except for the application main file, there are configuration files for the RPMsg-Lite (rpmsg_config.h) and eRPC
(erpc_config.h), located in the following folder:
/boards/lpcxpresso54114/multicore_examples/erpc_matrix_multiply_rpmsg

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
20

NXP Semiconductors

eRPC example

Figure 10. Client user code

3.4.3 Multiprocessor server application
The “Matrix multiply” eRPC server project for multiprocessor applications is located in the
>/boards//multiprocessor_examples/
erpc_server_matrix_multiply_ folder.
Most of the multiprocessor application setup is the same as for the multicore application. The multiprocessor server
application requires server-related generated files (server shim code), server infrastructure files, and the server user code.
There is no need for server multicore infrastructure files (MCMGR and RPMsg-Lite). The RPMsg-Lite transport layer is
replaced either by SPI or UART transports. The following table shows the required transport-related files per each transport
type.

Table 3. Transport-related eRPC files for the server side application
SPI

/erpc_c/setup/erpc_setup_(d)spi_slave.cpp
/erpc_c/transports/erpc_(d)spi_slave_transport.h
/erpc_c/transports/
erpc_(d)spi_slave_transport.cpp

UART

/erpc_c/setup/erpc_setup_uart_cmsis.cpp

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

21

eRPC example

Table 3. Transport-related eRPC files for the server side application
/erpc_c/transports/erpc_uart_cmsis_transport.h
/erpc_c/transports/erpc_uart_cmsis_transport.cpp

3.4.3.1

Server user code

The server’s user code is stored in the main_server.c file, located in the /boards/
/multiprocessor_examples/erpc_server_matrix_multiply_/ folder.
The eRPC-relevant code with UART as a transport is captured in the following code snippet:
/* erpcMatrixMultiply function user implementation */
void erpcMatrixMultiply(Matrix matrix1, Matrix matrix2, Matrix result_matrix)
{
...
}
int main()
{
...
/* UART transport layer initialization, ERPC_DEMO_UART is the structure of CMSIS UART
driver operations */
erpc_transport_t transport;
transport = erpc_transport_cmsis_uart_init((void *)&ERPC_DEMO_UART);
...
/* MessageBufferFactory initialization */
erpc_mbf_t message_buffer_factory;
message_buffer_factory = erpc_mbf_dynamic_init();
...
/* eRPC server side initialization */
erpc_server_init(transport, message_buffer_factory);
...
/* Adding the service to the server */
erpc_add_service_to_server(create_MatrixMultiplyService_service());
...
while (1)
{
/* Process eRPC requests */
erpc_status_t status = erpc_server_poll();
/* handle error status */
if (status != kErpcStatus_Success)
{
/* print error description */
erpc_error_handler(status, 0);
...
}
...
}
}

3.4.4 Multiprocessor client application
The “Matrix multiply” eRPC client project for multiprocessor applications is located in the /
boards//multiprocessor_examples/erpc_client_matrix_multiply_/iar/ folder.

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
22

NXP Semiconductors

eRPC example

Most of the multiprocessor application setup is the same as for the multicore application. The multiprocessor server
application requires client-related generated files (server shim code), client infrastructure files, and the client user code. There
is no need for client multicore infrastructure files (MCMGR and RPMsg-Lite). The RPMsg-Lite transport layer is replaced
either by SPI or UART transports. The following table shows the required transport-related files per each transport type.

Table 4. Transport-related eRPC files for the client side application
SPI

/erpc_c/setup/erpc_setup_(d)spi_master.cpp
/erpc_c/transports/
erpc_(d)spi_master_transport.h
/erpc_c/transports/
erpc_(d)spi_master_transport.cpp

UART

/erpc_c/setup/erpc_setup_uart_cmsis.cpp
/erpc_c/transports/erpc_uart_cmsis_transport.h
/erpc_c/transports/erpc_uart_cmsis_transport.cpp

3.4.4.1

Client user code

The client’s user code is stored in the main_client.c file, located in the
/boards//multiprocessor_examples/
erpc_client_matrix_multiply_/

folder.
The eRPC-relevant code with UART as a transport is captured in the following code snippet:
...
extern bool g_erpc_error_occurred;
...
/* Declare matrix arrays */
Matrix matrix1 = {0}, matrix2 = {0}, result_matrix = {0};
...
/* UART transport layer initialization, ERPC_DEMO_UART is the structure of CMSIS UART
driver operations */
erpc_transport_t transport;
transport = erpc_transport_cmsis_uart_init((void *)&ERPC_DEMO_UART);
...
/* MessageBufferFactory initialization */
erpc_mbf_t message_buffer_factory;
message_buffer_factory = erpc_mbf_dynamic_init();
...
/* eRPC client side initialization */
erpc_client_init(transport, message_buffer_factory);
...
/* Set default error handler */
erpc_client_set_error_handler(erpc_error_handler);
...
while (1)
{
/* Invoke the erpcMatrixMultiply function */
erpcMatrixMultiply(matrix1, matrix2, result_matrix);
...
/* Check if some error occured in eRPC */
if (g_erpc_error_occurred)
{
/* Exit program loop */
break;
}

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

23

eRPC example
}

...

3.5 Running the eRPC application
Follow the instructions in Getting Started with MCUXpresso SDK (document MCUXSDKGSUG) (located in the
/docs folder), to load both the primary and the secondary core images into the on-chip

memory, and then effectively debug the dual-core application. After the application is running, the serial console should look
like:

Figure 11. Running the eRPC application
For multiprocessor applications that are running between PC and the target evaluation board or between two boards, follow
the instructions in the accompanied example readme files that provide details about the proper board setup and the PC side
setup (Python).

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
24

NXP Semiconductors

Other uses for an eRPC implementation

4 Other uses for an eRPC implementation
The eRPC implementation is generic, and its use is not limited to just embedded applications. When creating an eRPC
application outside the embedded world, the same principles apply. For example, this manual can be used to create an eRPC
application for a PC running the Linux operating system. Based on the used type of transport medium, existing transport
layers can be used, or new transport layers can be implemented.
For more information and erpc updates see the github.com/EmbeddedRPC.

5 Revision history
To provide the most up-to-date information, the revision of our documents on the Internet are the most current. Your printed
copy may be an earlier revision.
This revision history table summarizes the changes contained in this document since the last release.

Table 5. Revision history
Revision
number

Date

Substantive changes

0

09/2015

Initial release

1

04/2016

Updated to Kinetis SDK v.2.0 and Multicore SDK v.1.1.0

2

09/2016

Updated to Kinetis SDK v.2.0 and Multicore SDK v.2.0.0

3

09/2016

Updated to Multicore SDK v.2.1.0 and the eRPC v.1.3.0
Added new sections covering multiprocessor applications.

4

03/2017

Updated to Multicore SDK v.2.2.0 and the eRPC v.1.4.0

5

11/2017

Updated to Multicore SDK v.2.3.0 and the eRPC v.1.5.0
MCUXpresso SDK 2.3.0 release

6

05/2018

Editorial updates for MCUXpresso SDK v2.3.1 and v2.4.0

eRPC Getting Started User’s Guide, Rev. 6, 05/2018
NXP Semiconductors

25

How to Reach Us:
Home Page:
nxp.com
Web Support:
nxp.com/support

Information in this document is provided solely to enable system and software
implementers to use NXP products. There are no express or implied copyright
licenses granted hereunder to design or fabricate any integrated circuits based
on the information in this document. NXP reserves the right to make changes
without further notice to any products herein.
NXP makes no warranty, representation, or guarantee regarding the suitability of
its products for any particular purpose, nor does NXP assume any liability arising
out of the application or use of any product or circuit, and specifically disclaims
any and all liability, including without limitation consequential or incidental
damages. “Typical” parameters that may be provided in NXP data sheets and/or
specifications can and do vary in different applications, and actual performance
may vary over time. All operating parameters, including “typicals,” must be
validated for each customer application by customerʼs technical experts. NXP
does not convey any license under its patent rights nor the rights of others. NXP
sells products pursuant to standard terms and conditions of sale, which can be
found at the following address: nxp.com/SalesTermsandConditions.
NXP, the NXP logo, NXP SECURE CONNECTIONS FOR A SMARTER
WORLD, Freescale, the Freescale logo, Kinetis, and Tower are trademarks of
NXP B.V. All other product or service names are the property of their respective
owners. Arm, Arm Powered, Cortex, Keil, and μVision are registered trademarks
of Arm Limited (or its subsidiaries) in the EU and/or elsewhere. All rights
reserved.
© 2018 NXP B.V.

Document Number MCSDKERPCGSUG
Revision 6, 05/2018



Source Exif Data:
File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.4
Linearized                      : No
Has XFA                         : No
XMP Toolkit                     : Adobe XMP Core 5.6-c015 84.159810, 2016/09/10-02:41:30
Fsl Dita Plugin Version         : 20160510
Fsl Ssds Version                : 4.7.1
Format                          : application/pdf
Creator                         : NXP Semiconductors
Title                           : eRPC Getting Started User’s Guide
Description                     : This Getting Started User's Guide shows software developers..how to use Remote Procedure Calls (RPC) in embedded..multicore microcontrollers (eRPC).
Subject                         : This Getting Started User's Guide shows software developers, how to use Remote Procedure Calls (RPC) in embedded, multicore microcontrollers (eRPC).
Create Date                     : 2018:05:03 12:57:55-07:00
Creator Tool                    : AH XSL Formatter V6.1 MR2 for Linux64 : 6.1.6.12685 (2013/09/18 10:39JST)
Modify Date                     : 2018:05:14 00:50:07-05:00
Metadata Date                   : 2018:05:14 00:50:07-05:00
Producer                        : Antenna House PDF Output Library 6.1.425 (Linux64); modified using iText® 5.1.3 ©2000-2011 1T3XT BVBA
Trapped                         : False
Document ID                     : uuid:49fc6feb-23fb-4af2-a074-c2775abf3940
Instance ID                     : uuid:c021cbaf-bd67-49c3-a8e8-98b16103f1a7
Page Mode                       : UseOutlines
Page Count                      : 26
Author                          : NXP Semiconductors
Keywords                        : This, Getting, Started, User's, Guide, shows, software, developers, how, to, use, Remote, Procedure, Calls, (RPC), in, embedded, multicore, microcontrollers, (eRPC).
Warning                         : [Minor] Ignored duplicate Info dictionary
EXIF Metadata provided by EXIF.tools

Navigation menu